Cellular carriers already know where you are thanks to your phone. On paper it makes sense: Service providers like AT&T need to know your location in order to relay calls and texts, determining your position from cell towers. But now, according to a new report in the Washington Post, surveillance companies are selling advanced tracking systems that take advantage of this technology, making it possible even for small governments to track users anytime, anywhere—for days or even weeks at a time with stunning accuracy.

Welcome to the future of the surveillance biz.

How did the Washington Post obtain this information? From pamphlets, apparently. The Post reports that companies like Verint Systems allegedly offer surveillance systems to would-be buyers like law enforcement officials, in conferences that are closed to the public:

A 24-page marketing brochure for SkyLock, a cellular tracking system sold by Verint, a maker of analytics systems based in Melville, N.Y., carries the subtitle "Locate. Track. Manipulate." The document, dated January 2013 and labeled "Commercially Confidential," says the system offers government agencies "a cost-effective, new approach to obtaining global location information concerning known targets."

The brochure includes screen shots of maps depicting location tracking in what appears to be Mexico, Nigeria, South Africa, Brazil, Congo, the United Arab Emirates, Zimbabwe and several other countries. Verint says on its Web site that it is "a global leader in Actionable Intelligence solutions for customer engagement optimization, security intelligence, and fraud, risk and compliance," with clients in "more than 10,000 organizations in over 180 countries."

It's unclear how much these tracking systems go for, but they apparently work: The Post notes that one such system was used by a security researcher to easily find the reporter's position.

While cutting-edge government agencies like the NSA in the U.S. and GHCQ in Britain have long had the capability to track targets, these technologies make it possible for less well-financed countries and other entities to track targets inconspicuously.